Say your goals do involve riding the horse. If you're a beginner, or have limited experience with being on a horse, you'll have to acquire new physical skills and condition your body to new ways of moving. Even if you have logged many hours in the saddle, you're never "done" improving as a rider.
Generally, a rider's learning curve consists of three stages:
Stage 1: Development of the physical skills (strength, coordination and balance) to stay in the saddle while the horse is moving.
Stage 2: Achieving harmony with the horse as it moves; i.e. not impeding or unbalancing the horse as it moves with a rider on board. This can now be called passive riding.
Stage 3: Ability to influence the horse's movements and behaviors in a positive way. Includes control of the horse's actions to ensure safety, and to impose the rider's goals of how, where and when the horse moves.
In the last stage, two-way communication between rider and horse is necessary. From this point on, any interaction between horse and person constitutes a training process; whether the person is on the ground or in the saddle.